Folding billiard table
BACKGROUND OF THE INVENTION 
     The present invention relates to a folding billiard table contrasting the conventional stationary one without folding means. The conventional and widely used billiard table is known to occupy a fairly large space and is inconvenient to transport or handle. Due to its heavy weight and rigidity requirement, a folding billiard table has never been invented before. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention to provide a billiard table with folding means therein to enable a folding operation after use so as to minimize the space occupied and to allow further easy handling. 
     A further object of the present invention is to provide a folding billiard table while maintaining its rigidity requirement. 
     These and additional objects, if not set forth specifically herein, will be readily apparent to those skilled in the art from the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view of a folding billiard table according to the present invention, when in the normal unfolded configuration; 
     FIG. 2 is a fragmentary perspective view of the folding billiard table according to the present invention showing only a part of the table with the supporting means, when in the folded configuration; 
     FIG. 3 shows a partial perspective view of FIG. 1 with a hinge in exploded view; 
     FIG. 4 illustrates a fragmentary perspective view of a portion of the center area of the folding billiard table according to the present invention; 
     FIG. 5 gives a perspective view of the tension means of the folding billiard table according to the present invention; 
     FIG. 6 gives a perspective view of the locking means according to the present invention; and 
     FIG. 7 is a cross-sectional view of the folding billiard table according to the present invention, when in the folded configuration. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The whole assembly, in accordance with the present invention, comprises substantially a table 11 formed of two symmetrical parts 12, 13, a pair of supporting means 22 with a plurality of linking bars used as linking elements within the whole assembly, and a center assembly 44 below the table 11. 
     In the upper face of the periphery of the table 11 there are fitted a pair of hinges 14 on opposite sides, each formed of two complementary parts, as shown in FIG. 3, which serve as a connection between the two symmetrical parts 12, 13. 
     There are a pair of grooves 15 on the underside of each part 12, 13 near the center thereof, which are adapted to receive respectively a pivotally stationary bar 23 further connected to a vertical supporting leg 24 and a pivotally movable bar 25 further connected to a supporting wheel leg 26. Adjacent to each said groove 15 is a seating 16 secured to the underside of said table 11 with a seat hole 17 in the center of each seating 16. Each seat hole 17 is used to fit therein a corresponding positioning screw 27 located at each end of an upper horizontal supporting leg 28, when the whole assembly is in normal unfolded configuration. 
     Each supporting means 22 substantially comprises one said horizontal supporting 28 and two vertical supporting legs 24, joined in an inverted-U shape, a pair of said supporting wheel legs 26, a pair of aforementioned stationary and movable bars 23 and 25 respectively, and other reinforcing and connecting elements connected in the manner further described hereinbelow. There are generally three stationary reinforcing bars 29 disposed between said supporting legs 24, 28, 24, with one horizontal and two angled. An inwardly protruding bar 30 is also welded to said horizontal supporting leg 28 and slightly inclined toward the ground. Said vertical supporting leg 24 and said supporting wheel leg 26 are linked therebetween via a plurality of connecting plates 31 pivotally screwed thereon at two ends. The plane formed of said vertical supporting leg 24, said connecting plates 31, and said supporting wheel leg 26 is substantially normal to the general plane of said table 11. 
     When in normal unfolded configuration, as shown in FIG. 1, only said vertical supporting legs 24 will contact the ground with seat studs 32, while said supporting wheel legs 26 will accordingly lift up due primarily to the connecting plates 31. 
     When in the folded configuration, as shown in FIG. 2 and also in FIG. 7, the situation is similar to the above-mentioned normal unfolded configuration, but with said supporting wheel legs 26 instead contacting the ground with wheels 33 to make the whole assembly maneuverable for transporting or handling. 
     Referring to FIG. 4, said center assembly 44 below the table 11 includes a center spindle 45 extending under the middle of the table 11, a pair of gears 46 engaged with each other, a pair of gear racks 47 askew relative to each other and both engaged with said gears 46 at an outer position thereof while the relative contacting relation is secured by a pair of angle brackets 48 as shown. Two positioning plate protrusions 49 having two holes 50, therethrough entered downward from said center spindle 45 disposed to hold said gears 46 and accordingly said gear racks 47 in position. 
     There is further a traverse bar 51, affixed to a plate protrusion 49, see FIG. 7, with each end pivotally connected to link a respective bar 52 which is each pivotally connected to said protruding bars 30, see FIG. 1. By this connection, the weight of the center assembly 44 is ascertained to be more evenly distributed over the supporting means 22. 
     On the underside of said table 11 is provided a tension block 53, as shown in FIG. 5, which is effected, when the table 11 is in the normal unfolded configuration, to stabilize the table 11 through its interconnection. Beside said tension block 53 is provided a spring holder 54 with one end connected to one end of a spring 55. Another end of the spring holder 54 is connected to a reinforcing plate 56 disposed between said stationary bar 23 and said vertical supporting leg 24. Also on the underside of the table 11 but on an opposite side of the center assembly 44 from said spring 55, there is disposed a locking mechanism 57 including a locking handle 58. When the table 11 is in the normal unfolded configuration, said locking handle 58, pivotally connected to a first stationary base 59, may be rotated to engage with a locking groove 60 formed on a secondary stationary base 61. Said first and second stationary base 59, 61 are, for example, made of steel blocks and fixedly attached to the table 11. As shown in FIG. 6, the locking handle 58 preferably includes a stick 62 with a ball end 63. 
     Referring again to FIG. 1 and FIG. 2, during opening the table 11 to the normal unfolded configuration, said gear racks 47, which are in essence pivotally engaged with said table 11 and held in engagement with said gears 46 by said angle brackets 48, are both ensured to slide or move the same amount in relation to said gears 46, which are in essence rotatable within said holes 50 of said plate protrusions 49, and accordingly may provide accurate configuration in accordance with this invention. Still during opening the table 11 to be the normal unfolded configuration, the upward movement of the center assembly 44 will naturally force said stationary bars 23 as well as said vertical supporting legs 24 to descend via the connecting plates 31 pivotally disposed between the vertical supporting leg 24 and the supporting wheel legs 26, until the ground is contacted by said seat stud 32. The subsequently accompanying ascending movement of the supporting wheel leg 26 is then readily apparent. Also the seat holes 17 in the seatings 16 are adapted to correctly receive the positioning screws 27. 
     Furthermore, the matching of said tension block 53, the engagement of said locking mechanism 57, and the spring force due to the spring 55 being stretched all aid in the accurate interconnection between components and the rigidity of this invention. 
     Referring now to FIG. 1 and FIG. 7, to fold the table 11, first unlock the locking mechanism 57 by rotating said locking handle 58, then slowly move down the center assembly 44 and/or push inward the supporting means 22 until said supporting wheel legs 26 eventually contact the ground, similar to the aforementioned situation, the following ascending movement of said vertical supporting leg 24 is again readily apparent. When in the folded configuration, shown best in FIG. 7, the smaller space occupied and the wheels 33 for easy transporting or handling are clearly shown advantages of this invention. 
     While the present invention has been explained in relation to its preferred embodiment, it is to be understood that various modifications thereof will be apparent to those skilled in the art upon reading this specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover all such modifications as fall within the scope of the appended claims.